US2250216A - Electric switch - Google Patents

Description

July 22, 1941, J. yEnERM/lums Inventor: Josef` Biermanns, by KMU@ rfhs Attorney.

Patented July 22, 1941 UNITEDy STATES PATENT OFFICE 1 zasazls I ELECTRIC SWITCH Josef Biermanns, Berlin-Friedrichshagen, Germany, alsignor to General Electric-Company, a corporation of New York y Application June 11, 1940, Serial No. 339,989

` Germany June 3, 1939 (ci. zoo-soi Y 6 Claims.

My invention relates to improvements in eiecl tric switches and more particularly to improvements in disconnecting switches and especially desired between the blade and the stationary contact, a considerable force is required to release the blade member from the stationary contact member by the operating means which effects the angular movement oi the blade member. Moreover, when the disconnecting switches are mounted outdoors, which is usually the'v case with high operating voltages, the point of engagement of the blade member andl its cooperating stationary contact may become coated with ice so that the diiculty of separating the blade member and its cooperating contact member is greatly increased. To take care oi all these conditions in the design of the switch would require such a massive construction as to render the design economically unfeasible.

- One object of my invention is to provide an improved electric switch wherein the separation of the movable switch member and its cooperating contact member can be simply effected without undue strains on the various parts of the switch mechanism and without the necessityv vand contact separation movement but also to effect the angular movement of the blade member. These and other objects of my invention will appear in more detail hereinafter.

My invention will be better understood from the following description when considered in connection with the accompanying sheet o! drawings, and its scope will be pointed out in the appended claims. y

IIn the accompanying drawing Fig. l illustrates partly in elevation and partly in section a combinaticn circuit breaker and disconnecting switch embodying my invention, and Fig. 2 is a detail showing the end of the disconnecting switch blade member in engagement with its cooperating stationary contact member.

For the purpose of illustrating my invention, I have shown a'combined circuit breaker l and disconnecting switch 4 as supported on suitable insulators 5 and B extending upwardly from a suit--` able mounting'or basel. The insulator 5 may be forked with two arms B and 9 on which the circuit breaker 3 is mounted while the disconnecting switch 4 is mounted on the insulator arm 9 and the insulator 6.

As shown, the circuit breakers are of the type disclosed in United States Letters Patent 2,084,- 885 issued January 22, 1937 and assigned to the assignee of this invention. Such circuit breakers heads Il of suitable insulating material. The

interior of these heads is shaped to provide a cylinder I2 {o1- ghiding a piston I3 by which the contact I0 is retracted from circuit closing to circuit opening position against the bias of a spring I4 upon admission of a suitable fluid, such as air, under the necessary pressure into the air chamber i5 of the head. The contactoriilce is such as to permit the escape oi some of the uid around the contact for arc extinguishing pur-f poses. The operating-duid may be conducted from any suitable storage tank o 'r reservoir, not shown. through suitable means indicated as a conduit I6 which divides into two branchesy Il one for each of the headsv Il.A 'Ihese conduits or pipes may be mounted within the insulator l, as shown.

1 The disconnecting switch I is oi the angularly movable blade type comprising a movable conductor, such as a. blade Il which, as shown,v is mounted on a. pivot I9 suitably supported on-the insulator arm 9, as for example on the body structure of the right-hand extinguishing head Il. 'Cooperating with the tree and .oi the blade i8 is a stationary contactv member 20 'which is mounted on the insulator 8 and, as shown more clearly in Eig. 2, may be of the jaw type.

.Whilethe angular movement of the blade Il may be effected by any suitable mechanism, I preferably use an operating mechanism" ot 'the iluid pressure type. As shown, this operating mechanism comprises a piston 2l which is'moyable within a cylinder 22 in the right-hand c x.- tinguishing head upon admission oi' operating Iiuid through the conduit I1 inthe insulator. arm

9 to swing the blade I8 from the closed position, shown in solid lines, to the open position, shown in dotted lines. For this purpose, the piston 2I may be connected to the blade I8 by any suitable means which are herein illustrated as a piston rod 23 movable with the piston 2I and a connecting link 24 pivotally connected to the piston rod 23 and the blade I8. The pivotal connections of the link 24 and the proportioning of the parts are such that in the open position of the blade I8 the downward thrust of the blade due to gravity results in a substantially vertical load on the piston rod 23 so that there is no tendency for the switch blade to swing to the closed position.

In order to provide the necessary conducting path between the circuit breaker contact I8 and the disconnecting switch blade I8, suitable means, such as a flexible lead 25, may extend between the pistons I3 and 2| and another exible lead 26 between the piston rod 23 and the blade I8.

For effecting the closing movement of the blade I8, the operating fluid may be led through a conduit 21 extending upwardly through the insulator 5 and the arm 9 thereof into the cylinder 22 so that, upon admission of iiuid to this conduit, the piston 2I is moved from 'right to left, as viewed in Fig. 1, to effect a clockwise movement of the blade I8 into engagement with the contact 20.

In order to eiect an initial movement of the blade I8 relatively to the contact 2II without the necessity of the extreme forces that would have to be applied to the blade at the pivoted end thereof, particularly in high contact pressure switches and switches which are exposed to ice conditions, and to avoid the heavy blade structure which would be required to carry heavy bending stresses, I provide, in accordance with my invention, uid pressure operated means for exerting a force directly on one of the cooperating contact members of the disconnecting switch adjacent their point of engagement tending to effect the separation of the members. As illustrated, this means comprises a'cylinder 28 which may be formed within the free end of the blade I8 to guide a piston 29 and movable within which is a piston rod 30 through an opening in the cylinder 28 to engage the contact 20 or the support therefor. For actuating the piston 28 downwardly to force the blade I8 upwardly out of the contact 20, a conduit or fluid passage 8i, may be mounted on or constructed as a part of the blade I8. Ihis conduit 8| is connected to the air chamber of the right-hand head II through a port 32 and a suitably flexible connecting pipe 33 to allow for the angular movement of the blade. Thus, upon the admission of air under the desired pressure into the conduit I6, the contacts I Il are separated, the pressure releasing action is effected at the contact 20 and the switch blade I8 is swung counter-clockwise to the open position shown in dotted lines.

While I have shown the pressure releasing piston 29 mounted on the end of the blade I8 so as to push the blade away from the contact, it will be obvious to those skilled in the art that the position of the parts may be reversed so that the cylinder for the piston 28 is mounted on the insulator 8 to exert a thrust upwardly against the blade rather than downwardly against the contact, as shown in Fig. 1. Of course, in this case the admission of air to the operating cylinder could be through a suitable conduit mounted in the insulator 8, for example, as will be obvious to those skilled in the art.

While I have shown and described my invention in considerable detail, I do not desire to be limited to the exact arrangements shown, but seek to cover in the appended claims all those modincations that fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. An electric switch comprising an electric current conducting member mounted for angular movement, a stationary contact member engageable by said conducting member upon angular movement thereof in one direction, fluid pressure operated means for exerting a force' directly on one of said members adjacent their point of engagement tending to effect the separation of the members, and means for conducting uid to said pressure-operated means by way of said electric current conducting member.

2. An electric switch comprising a pivotally mounted blade member, a stationary contact member engageable by the free end of said blade member upon angular movement thereof in one direction, and pneumatic means for exerting a force directly on one of said members adjacent their point of 'engagement tending to effect the separation of the members comprising relatively movable cooperating means mounted adjacent the free end of said blade member and means for conducting air to said relatively movable cooperating means by way of said blade member.

3. An electric switch comprising a pivotally mounted blade. member, a stationary contact member engageable by said blade member upon angular movement thereof in one direction, and pneumatic means for exerting a force directly on one of said members adjacent their point of engagement tending to eifect the separation of the members comprising relatively movable cooperating means mounted adjacent the free end of said blade member.

4. An electric switch comprising. a pivotally mounted blade member, a stationary contact member engageable by the free end of said blade member upon angular movement thereof in one direction, and pneumatic means for exerting a force directly on one of said members tending to effect the separation thereof comprising a cylinder and a piston mounted adjacent the free end of said blade member.

5. An electric switch comprising a pivotally mounted blade member, a stationary contact member engageable by the free end of said blade member upon angular movement thereof in one direction, and pneumatic means for exerting a force directly` on said contact member tending to effect the separation of said members comprising a cylinder and cooperating piston carried by said blade member near the free end thereof.

6. An electric switch comprising an electric current conducting member mounted for angular movement, a stationary contact member engageable by said conducting member upon angular movement thereof in one direction, actuating means for effecting angular movement of said conducting member into and out of engagement with said contact member, and uid pressure operated means independent of said actuating means for exerting a force adjacent the point of engagement of said members and tending to effect the yseparation of said members when they are in engagement.

JOSEF BIERMANNS.

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